1. Field of the Invention
The present invention relates to a cassette loading apparatus arranged to cause a tape cassette containing therein a tape for a VTR (video tape recorder) or the like to ascend and descend, and also relates to a recording or reproducing apparatus, such as a VTR, which is provided with the cassette loading apparatus.
2. Description of Related Art
An example of the conventional arrangement of a cassette loading apparatus mounted in a video camera or the like is described below with reference to FIGS. 1 to 9. FIGS. 1, 2 and 3 are side views showing, by way of example, the arrangement of a conventional cassette loading apparatus. A cassette holder 102 is arranged to hold a tape cassette 101. A cassette pressing spring 103 is provided at the holder 102 for keeping the cassette 101 in place. A connection shaft 104 is mounted on a support part of the holder 102. A synchronizing lever 105 is arranged to swing integrally with the connection shaft 104. A lever 106 is connected to the synchronizing lever 105 at about the center part of the synchronizing lever 105 by a shaft 106c and is arranged to form an X-link in conjunction with the synchronizing lever 105. A lock lever 107 is arranged to lock the holder 102. Reference numeral 108 denotes a subchassis arranged to hold the cassette 101. The subchassis 108 is provided with a lock member 109 which is arranged to mesh with the lock lever 107. Cassette receiving members 110 are arranged to receive the cassette 101. Holder receiving members 111 are arranged to receive the holder 102. A lid opening member 112 is provided for opening lids of the cassette 101. A coiled spring 113 is hung between the lock lever 107 and the lever 106 to constantly urge the holder 102 upward and to urge the lock lever 107 to swing clockwise on a shaft 102b which is provided on the holder 102. A switch 114 is arranged to detect the locked state of the holder 102. A main chassis 115 is arranged to hold the subchassis 108 in such a way as to allow the subchassis 108 to slide. Guide shafts 116 are disposed on the main chassis 115 to support and guide the subchassis 108. A lock lever driving member 117 is also disposed on the main chassis 115. A switch holder 123 is arranged to secure the switch 114 to a side surface of the subchassis 108. A flexible printed circuit board 124 is arranged to provide the switch 114 with wiring.
Further, an X-link mechanism of the cassette loading apparatus which is formed by the above-stated parts is also arranged in the same manner on the opposite side of the tape cassette 101, which is not shown. The connection shaft 104 is provided for synchronizing the two X-link mechanisms formed on the two sides of the cassette 101 by interlocking the synchronizing lever 105 on one side with that of the X-link mechanism on the other side.
Referring to FIGS. 1, 2 and 3, the operation of the cassette loading apparatus is described as follows.
The cassette 101 is inserted into the holder 102 in the direction of an arrow A, as shown in FIG. 1. When the upper part of the holder 102 is pushed down against the upward urging force of the spring 113, the shaft 105a of the synchronizing lever 105 and the shaft 106a of the lever 106 slide respectively along a cam slot 108a of the subchassis 108 and the cam slot 102a of the holder 102 to cause the holder 102 and the cassette 101 to descend.
Then, a pin 107a which is provided on the lock lever 107 moves along a slant surface of the lock member 109. Further, the lid opening member 112, which is provided on the subchassis 108, pushes upward the front lid 101a of the cassette 101, so that the front lid 101a and the back lid 101b of the cassette 101 are made to swing on a shaft 101c. As a result, the lids of the cassette 101 come to open.
When the holder 102 and the cassette 101 reach the descended position of the holder 102, as shown in FIG. 2, the pin 107a of the lock lever 107 overrides a hook part of the lock member 109 to be caused to plunge into the lower part of the lock member 109 by the urging force exerted on the lock lever 107, thereby bringing about a locked state of the lock lever 107 in mesh with the lock member 109. In this instance, the plunging action of the lock lever 107 causes a switch operating part 107b which is provided on the lock lever 107 to push the knob 114a of the detecting switch 114. The detecting switch 114 then turns on to detect that the holder 102 has been locked. Further, the front lid 101a and the back lid 101b of the cassette 101 are kept opened at a predetermined angle defined by the lid opening member 112.
FIG. 4 is a diagram showing the cassette 101 in the state of having its lids opened. In this state, the front lid 101a has swung on the shaft 101c, and the back lid 101b has been moved in association with the front lid 101a to shift to the upper portion of the cassette 101.
When the locked state of the holder 102 is detected by the detecting switch 114, a slide mechanism which has a DC motor (not shown) as a drive source thereof acts to cause the subchassis 108 holding the cassette 101 to slide to the right, as viewed in FIG. 2, to bring the subchassis 108 into a recording or reproducing position (FIG. 3). Then, a tape is pulled out from the cassette 101 by a tape loading mechanism to bring about a recordable or reproducible state.
In this state, the cassette 101 is pushed by the action of the cassette pressing spring 103 (FIG. 1) against the cassette receiving members 110, which define a datum height of the cassette 101 on the subchassis 108. There is thus provided some clearance between the bottom of the holder 102 and that of the cassette 101 to prevent the two from coming into contact with each other.
FIGS. 5, 6 and 7 show the cassette loading apparatus as viewed from the direction of the arrow A in FIG. 1. FIG. 5 is a side view showing the cassette loading apparatus, as viewed from the cassette inserting direction, in a state obtained while the cassette 101 is in process of descending. The cassette 101 descends while being pushed and held on the lower receiving surface of the holder 102 by the action of the cassette pressing spring 103.
FIG. 6 is a sectional view showing the cassette loading apparatus, as viewed from the cassette inserting direction, in a state where the holder 102 has completely descended as shown in FIG. 2 with the holder 102 locked by the intermeshing of the lock lever 107 and the lock member 109. In this instance, in order to make the pin 107a of the lock lever 107 (FIG. 1) plunge into the lock member 109 for intermeshing, it is necessary for the holder 102 to descend excessively from the locked position (overstroke). Hence, the holder 102 is pushed down lower than the height thereof in the locked position (HL in FIG. 6), and is then brought back to the locked position.
FIG. 7 shows the cassette loading apparatus in a state where the holder 102 has descended to the extent of such an overstroke. After the state shown in FIG. 7, the lock lever 107 comes to mesh with the lock member 109. At the same time, the holder 102 is caused to ascend by the action of the spring 113 (FIG. 1) to bring about the state shown in FIG. 6.
When the holder 102 is caused to descend by pushing the holder 102 down toward the locked position or by some other load imposed thereon, the holder receiving members 111 receive the lower surface of the holder 102 to restrict the height of the holder 102. The height of the holder receiving members 111 is set at a height position corresponding to the overstroke necessary for the lock mechanism as mentioned above.
FIGS. 8 and 9 are plan views showing the subchassis 108 as viewed from above and, particularly, more clearly showing the sliding action thereof. In FIGS. 8 and 9, there are illustrated a recording and reproducing drum 118, a capstan 119, reel mounts 120, a cassette memory terminal 121, and tape guides 122.
Further, referring to FIGS. 8 and 9, slide slots 108b are arranged in the subchassis 108 to allow guide shafts 116 to slide there. Reference numeral 101d denotes the tape. As shown in FIGS. 8 and 9, the slide slots 108b are formed along the two ends of the subchassis 108. The subchassis 108 is provided further with an escape hole 108c which is formed in an area where the fore end part of the lock lever 107 acts by piercing therethrough. With the holder 102 in the descended state, the fore end part of the lock lever 107 protrudes from the lower side of the subchassis 108, as shown in FIGS. 2 and 3.
FIG. 8 shows the cassette loading apparatus in such a position as to allow the cassette to be inserted and loaded as shown in FIGS. 1 and 2. When the locked state of the holder 102 is detected, as mentioned above, the subchassis 108 slides upward as viewed in FIG. 8. At the same time, the tape 110d is pulled out from the cassette 101 by the tape guides 122. With the tape 101d pulled out, a predetermined tape path is formed as shown in FIG. 9 to permit recording or reproduction on or from the tape 101d. With the cassette loading apparatus in this state, the capstan 119 causes the tape 110d to travel at a predetermined speed. The reel mounts 120 are in mesh with reel hubs arranged within the cassette 101 in such a way as to take up and wind at a predetermined torque the tape 101d sent out forward by the capstan 119 in a known manner.
In taking out the cassette from the cassette loading apparatus, the conventional arrangement acts as follows. Upon receipt of a command to eject the cassette 101, the subchassis 108 makes an outward slide motion, as shown in FIGS. 2 and 8, reversely to the above-stated inward slide motion. At the same time, the tape 101d is rewound into the cassette 101. After that, the lock lever driving member 117 on the main chassis 115 moves in the direction of an arrow B shown in FIG. 2. This causes the lock lever 107 to swing counterclockwise against the urging force of the spring 113 to cancel the interlocking of the lock lever 107 and the lock member 109. The holder 102 is thus unlocked to be allowed to ascend by the lifting force of the spring 113, then moving to the cassette-taking-out position as shown in FIG. 1.
In the example of the above-mentioned conventional arrangement, however, the levers and the detecting switches, etc., have not been arranged in a manner apposite to a reduction in size of the cassette loading apparatus.
In the first place, since the connection shaft 104 is disposed on the upper part of the holder 102, the mechanism in the upper part of the holder 102 has a large dead space, which makes a reduction in thickness of the cassette loading apparatus difficult.
Further, in order to minimize a space to be occupied by a deck of the cassette loading apparatus, the connection shaft 104 must be disposed as close as possible to the cassette lids to permit the effective use of a space available above the upper surface of the cassette. However, in the case of the example of the conventional cassette loading apparatus, the detecting switch, the switch holder, the flexible printed circuit board for connection, etc., prevent the connection shaft 104 from being disposed close to the cassette lids. In other words, in order to have the X-link mechanism and the cassette detecting switch interposed in between the cassette 101 and the subchassis 108, it is necessary for avoiding interference with levers, etc., to increase a space in the direction of width of the cassette loading apparatus.
Further, in order that the connection shaft 104 is disposed in the neighborhood of the cassette lids, the lock lever 107 must be disposed on the cassette inserting side to avoid interference with the synchronizing lever 105, as in the case of the example of the conventional arrangement. However, as shown in FIG. 8, it becomes necessary to have the hole 108c which has the lock lever 107 piercing therethrough located adjacent to the slide slot 108b of the subchassis 108. This necessitates a distance xe2x80x9cdxe2x80x9d shown in FIG. 8 to be sufficiently large to ensure a necessary strength and thus also prevents a reduction in size in the direction of width of the cassette loading apparatus.
Further, in the example of the conventional arrangement described above, the lid opening member 112 is disposed on the subchassis 108. Thus, the location of the lid opening member 112 also lowers the degree of latitude allowed for design work and also prevents a reduction in size of the cassette loading apparatus.
The arrangement of the conventional cassette loading apparatus described by way of example above thus makes it difficult to minimize the size of the cassette loading apparatus both in the directions of height and width.
Under such a background, the invention is directed to the solution of the problem of the prior art described in the foregoing. It is, therefore, an object of the invention to provide a cassette loading apparatus arranged to minimize a dead space caused by a mechanism of the upper part of a holder and to permit the effective use of the space of the upper part of the holder for the purpose of reducing the size of the cassette loading apparatus.
Further, it is another object of the invention to optimize the positional arrangement of levers, a lid opening member, a detection switch, etc., which constitute the cassette loading apparatus, for the purpose of reducing the size of the cassette loading apparatus.
To attain the above objects, in accordance with an aspect of the invention, there is provided a cassette loading apparatus, which comprises a holder arranged to hold a cassette, and a link mechanism arranged to support the holder with a plurality of levers in such a way as to allow the holder to ascend and descend between an ascended position and a descended position with respect to a chassis, wherein the link mechanism includes a pair of levers which are disposed respectively on two opposite sides of the holder, the pair of levers being formed integrally with each other through a connection part arranged above an upper part of the cassette.
These and further objects and features of the invention will become apparent from the following detailed description of preferred embodiments thereof taken in connection with the accompanying drawings.